Location: Pewter City
Gym Leader: Brock
Specialty: Rock-type

Gym Leader Brock	Onix	Kabutops	Omastar	Aerodactyl	Golem
Battle Type Items	Level 56	Level 56	Level 56	Level 56	Level 57
	Attacks: Stealth Rock Iron Tail Rock Slide Earthquake	Attacks: X-Scissor Rock Slide Aqua Jet Brick Break	Attacks: Blizzard Hydro Pump Seismic Toss Reflect	Attacks: Crunch Rock Slide Earthquake Iron Tail	Attacks: Earthquake Rock Slide Fire Punch Thunder Punch

Location: Cerulean City
Gym Leader: Misty
Specialty: Water-type

Gym Leader Misty	Golduck	Dewgong	Starmie	Vaporeon	Gyarados
Battle Type Items	Level 56	Level 56	Level 56	Level 56	Level 57
	Attacks: Scald Psychic Ice Beam Light Screen	Attacks: Aqua Jet Ice Shard Waterfall Iron Tail	Attacks: Hydro Pump Dazzling Gleam Psychic Thunderbolt	Attacks: Hydro Pump Quick Attack Blizzard Shadow Ball	Attacks: Outrage Crunch Waterfall Iron Tail

Location: Vermilion City
Gym Leader: Lt. Surge
Specialty: Electric-type

Gym Leader Lt. Surge	Electrode	Jolteon	Electabuzz	Magneton	Raichu
Battle Type Items	Level 56	Level 56	Level 56	Level 56	Level 57
	Attacks: Mirror Coat Explosion Thunderbolt Foul Play	Attacks: Thunder Shadow Ball Reflect Quick Attack	Attacks: Thunder Punch Ice Punch Fire Punch Brick Break	Attacks: Thunder Flash Cannon Tri Attack Hyper Beam	Attacks: Thunder Punch Iron Tail Brick Break Quick Attack

Location: Celadon City
Gym Leader: Erika
Specialty: Grass-type

Gym Leader Erika	Tangela	Parasect	Victreebel	Exeggutor	Vileplume
Battle Type Items	Level 56	Level 56	Level 56	Level 56	Level 57
	Attacks: Mega Drain Sludge Bomb Reflect Power Whip	Attacks: Spore Leech Life Brick Break Solar Beam	Attacks: Power Whip Poison Jab Reflect Swords Dance	Attacks: Psychic Sludge Bomb Solar Beam Hyper Beam	Attacks: Moonblast Sludge Bomb Petal Dance Stun Spore

Location: Fuchsia City
Gym Leader: Koga
Specialty: Poison-type

Gym Leader Koga	Tentacruel	Golbat	Weezing	Venomoth	Muk
Battle Type Items	Level 56	Level 56	Level 56	Level 56	Level 57
	Attacks: Hydro Pump Toxic Sludge Bomb Mega Drain	Attacks: Crunch U-turn Fly Leech Life	Attacks: Fire Blast Thunder Sludge Bomb Toxic	Attacks: Mega Drain Sludge Bomb Psychic Bug Buzz	Attacks: Sludge Bomb Moonblast Mega Drain Dark Pulse

Location: Saffron City
Gym Leader: Sabrina
Specialty: Psychic-type

Gym Leader Sabrina	Mr. Mime	Jynx	Hypno	Slowbro	Alakazam
Battle Type Items	Level 56	Level 56	Level 56	Level 56	Level 57
	Attacks: Psychic Dazzling Gleam Reflect Light Screen	Attacks: Psychic Blizzard Shadow Ball Lovely Kiss	Attacks: Dream Eater Hypnosis Thunder Punch Fire Punch	Attacks: Psychic Ice Beam Shadow Ball Scald	Attacks: Psychic Dazzling Gleam Shadow Ball Tri Attack

Location: Cinnabar Island
Gym Leader: Blaine
Specialty: Fire-type

Gym Leader Blaine	Magmar	Rapidash	Ninetales	Flareon	Arcanine
Battle Type Items	Level 56	Level 56	Level 56	Level 56	Level 57
	Attacks: Fire Punch Thunder Punch Brick Break Will-O-Wisp	Attacks: Flare Blitz Quick Attack Megahorn Drill Run	Attacks: Fire Blast Quick Attack Dark Pulse Solar Beam	Attacks: Flare Blitz Quick Attack Superpower Iron Tail	Attacks: Flare Blitz Outrage Crunch Play Rough

Location: Viridian City
Gym Leader: Blue
Specialty: None

With Giovanni having left Viridian City, Blue has taken his place as leader of the Viridian City Gym. He has the ability to Mega Evolve his Charizard

Gym Leader Blue	Tauros	Gyarados	Aerodactyl	Alakazam	Exeggutor	Charizard
Battle Type Items	Level 66	Level 66	Level 66	Level 66	Level 66	Level 68
	Attacks: Double-Edge Earthquake Rock Slide Iron Tail	Attacks: Waterfall Crunch Outrage Earthquake	Attacks: Rock Slide Crunch Iron Tail Earthquake	Attacks: Dazzling Gleam Reflect Psychic Foul Play	Attacks: Power Whip Psychic Stomp Light Screen	Attacks: Fire Blast Hyper Beam Air Slash Dragon Pulse